UK High Court Clears PATHWAYS Puberty Blocker Trial as Legal Challenge Thrown Out

The UK High Court has cleared the way for the NHS (national health service) PATHWAYS puberty blocker trial to begin recruiting, after a judge refused a legal challenge brought by gender-critical campaigners seeking to halt it.

Mr Justice Chamberlain delivered the ruling on Friday 31 July, throwing out an attempt to bring a judicial review and refusing an emergency injunction that would have stopped children being enrolled while the case was heard. Recruitment was cleared to proceed from 1 August.

What the court decided

• The judge refused the claimants permission to proceed to a full judicial review, ending the challenge at the permission stage.
• He also refused their application for an emergency injunction to pause recruitment.
• In his ruling he found the trial had been commissioned by NHS England and designed by its co-sponsors with what he called conspicuous care, in consultation with expert bodies.
• He held that none of the grounds of challenge was arguable with a realistic prospect of success, and that the decision to approve the trial was a question of judgment for public health bodies rather than the courts.

Who brought the case

The challenge was mounted by the Bayswater Support Group, which describes itself as supporting parents of children who identify as trans, alongside psychotherapist James Esses and detransitioner Keira Bell. The defendants were the Health Research Authority and the Secretary of State for Health and Social Care, both of whom opposed the challenge.

The claimants argued that regulators, including the Medicines and Healthcare products Regulatory Agency, had acted unlawfully in approving the study, raising concerns about long-term effects and about the trial's design. Esses called the trial deeply unethical and highly dangerous and said he was consulting lawyers about a possible appeal. Bell described the ruling as a tragedy.

What the trial actually is

• PATHWAYS is an NHS-funded study run through a project at King's College London, which received £10.7 million in funding.
• Around 220 young people with persistent gender incongruence are expected to take part.
• Participants must already have received extensive psychological and social support through NHS Gender Services before they are eligible.
• Trans boys aged 11 and over and trans girls aged 12 and over will be permitted to join, subject to independent assessment.
• Roughly half of participants begin puberty suppression straight away, with the other half starting a year later, and all are monitored throughout.
• Enrolment requires informed assent from the young person and consent from a parent or legal guardian, with physical and mental health checks before and during the study.

The wider context

The trial exists because puberty blockers were removed from routine NHS care in the first place. Following the Cass Review, published in April 2024, which concluded the evidence base was remarkably weak, routine prescribing of the drugs for under-18s was banned outside a clinical trial. Ministers carved out PATHWAYS as the exception, on the argument that a properly designed study is the only way to answer the questions the ban was justified by.

That is the bind trans young people in England are now living inside. The same review that stripped away access to blockers is the reason the only remaining route to them runs through a monitored trial with a delayed-start arm, and the campaigners who went to the High Court this week were not fighting to restore broader access but to shut the last door entirely. They lost. Dr Hilary Cass herself said in June that more children would be harmed by not running the trial than by running it.

The research team welcomed the decision and said the safety and welfare of young people would remain its highest priority. Recruitment is now underway, and any appeal would be heard separately in the months ahead.